Nylon straps are used instead of cotton. All Seams are DOUBLE LOCK STITCHED with 100% Acrylic thread unlike most other tipis that are chain stitched with cotton or nylon and pull out very easily, just like the top of a potato sack. My Standard tipis are made from 12 oz. single fill industrial grade Natural Cotton Duck Fabric. In addition my tipis are reinforced at all stress points to withstand years of use in any weather condition. Please check my Q and A section for self help on water proofing, fire retarding and other helpful information including setting up your tipi and how to find poles.